Dormancy indication in sidelink communication systems

Abstract

Certain aspects of the present disclosure provide techniques for signaling a user equipment (UE) to put a sidelink (SL) component carrier (CC) into dormancy or take the SL CC out of dormancy, such as mode 1 or mode 2 sidelink communications. In one example, a method performed by a UE includes receiving an indication to put a first CC into dormancy; and putting an SL CC into a dormant state in response to the indication. In another example, a method includes transmitting an indication that the first UE will put an SL CC into a dormant state; and receiving an acknowledgment (ACK) of the indication.

The invention claimed is: 
     
         1 . An apparatus of a user equipment (UE) for wireless communication, comprising:
 memory; and   one or more processors coupled with the memory, the one or more processors, individually or collectively, being configured to:   receive an indication to put a first group of component carriers (CCs) including a first component carrier (CC) into dormancy by receiving a physical downlink control channel (PDCCH) via a primary CC, wherein the first CC comprises a CC for a secondary cell (SCell);   determine a sidelink (SL) CC that corresponds to the CC for the SCell;   receive a signal indicating a correspondence between the SL CC and the CC for the SCell; and   put the SL CC into a dormant state in response to the indication.   
     
     
         2 . The apparatus of  claim 1 , wherein the one or more processors, individually or collectively, are further configured to:
 refrain from decoding a control channel transmitted via the SL CC, when the SL CC is in the dormant state.   
     
     
         3 . The apparatus of  claim 1 , wherein the indication is received in a control message from a network entity, and wherein the control message does not affect a configuration of the SCell for the UE. 
     
     
         4 . The apparatus of  claim 3 , wherein the first group of CCs includes the SL CC. 
     
     
         5 . The apparatus of  claim 1 , wherein the one or more processors, individually or collectively, are further configured to receive the indication by receiving another indication to put the SL CC into the dormant state. 
     
     
         6 . A network entity for wireless communications, comprising:
 memory; and   one or more processors coupled with the memory, the one or more processors, individually or collectively, being configured to:   transmit an indication to a user equipment (UE) to put a first group of component carriers (CCs) including a first component carrier (CC) into dormancy by transmitting a physical downlink control channel (PDCCH) via a primary CC, wherein the first CC comprises a CC for a secondary cell (SCell);   determine a sidelink (SL) CC that corresponds to the CC for the SCell;   transmit a signal indicating a correspondence between the SL CC and the CC for the SCell; and   determine that the UE put the SL CC into a dormant state in response to the indication.   
     
     
         7 . The network entity of  claim 6 , wherein the indication is transmitted in a control message to the UE, wherein the control message does not affect a configuration of the SCell for the UE. 
     
     
         8 . The network entity of  claim 7 , wherein the first group of CCs includes the SL CC. 
     
     
         9 . The network entity of  claim 6 , wherein the one or more processors, individually or collectively, are further configured to:
 notify at least one other UE that the UE put the SL CC into the dormant state.   
     
     
         10 . The network entity of  claim 6 , wherein the one or more processors, individually or collectively, are further configured to:
 transmit the indication by transmitting another indication to put the SL CC into the dormant state.   
     
     
         11 . The network entity of  claim 6 , wherein the determination is based on receiving an acknowledgment (ACK) from the UE. 
     
     
         12 . An apparatus of a first user equipment (UE) for wireless communication, comprising:
 memory; and   one or more processors coupled with the memory, the one or more processors, individually or collectively, being configured to:
 transmit, to a second UE, an indication that the first UE will put a group of sidelink (SL) component carriers (CCs) including a first SL component carrier (CC) into a dormant state by transmitting a physical downlink control channel (PDCCH) via a primary CC; 
 receive, from the second UE, an acknowledgment (ACK) of the indication; 
 transmit, to a third UE, another indication that the first UE will put the group of SL CCs into the dormant state; 
 receive another ACK of the other indication from the third UE; and 
 refrain from putting the group of SL CCs into the dormant state until after receiving the ACK and the other ACK. 
   
     
     
         13 . The apparatus of  claim 12 , wherein the one or more processors, individually or collectively, are further configured to:
 refrain from decoding a control channel transmitted via the first SL CC, when the first SL CC is in the dormant state.   
     
     
         14 . The apparatus of  claim 12 , wherein the one or more processors, individually or collectively, are further configured to:
 transmit the indication by transmitting the indication to a network entity, wherein the ACK is received from the network entity.   
     
     
         15 . The apparatus of  claim 12 , wherein the one or more processors, individually or collectively, are further configured to:
 transmit the indication by transmitting the indication in at least one of a sidelink control information (SCI), a physical sidelink shared channel (PSSCH), or a physical sidelink feedback channel (PSFCH).   
     
     
         16 . The apparatus of  claim 12 , wherein transmitting the indication comprises the transmitting the indication via a primary SL CC different from the first SL CC. 
     
     
         17 . An apparatus of a first user equipment (UE) for wireless communication, comprising:
 memory; and   one or more processors coupled with the memory, the one or more processors, individually or collectively, being configured to:   receive an indication that a second UE will put a group of sidelink (SL) component carriers (CCs) including a first SL component carrier (CC) into a dormant state by receiving a physical downlink control channel (PDCCH) via a primary CC;   transmit an acknowledgment (ACK) of the indication;   transmit, to the second UE, another indication that the first UE will put the group of SL CCs into the dormant state;   receive another ACK of the other indication from the second UE; and   refrain from transmitting the ACK until after the first UE receives the other ACK.